How Flood Control Officials Plan To Fix Area Floodplain Maps

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New topographic and predictive rainfall data means more people in Harris County will be mapped in floodplains.

houstonpublicmedia.org - by Davis Land - November 26, 2018

When Hurricane Harvey left so much of Houston underwater, it highlighted a problem that’s been getting worse for years: Harris County’s existing floodplain maps just don’t work.

In the year since the historic storm, flood control officials have promised to change that, and they already had plans to redo the maps, but new data on the geography of the area and the amount of rainfall forecasters expect in the future means the new maps could look drastically different.

It’s crucial the maps are done right, as people are using the maps, meant to set flood insurance premiums, for more than they are intended . . . 

. . . Floodplain maps were originally intended to set flood insurance premiums, but people have started to use them as a guide to whether or not they’ll flood. Just before a storm, people could be making life or death decisions based on them.

Since more people are relying on the floodplain map for different reasons now, the Harris County Flood Control District is also adding a second map that will show “local hazards” like overland flooding – flooding outside of a bayou overtopping – as well as results of releases from the Addicks and Barker reservoirs.

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